Golondrina Cejiblanca

Identificación

The white-rumped swallow measures 13 centimetres (5.1 in) in length and weighs 17–21 grams (0.60–0.74 oz). It has an average wingspan of 115.7 millimetres (4.56 in). It has a white supraloral streak, a white streak above its eye, and black lores and ear coverts. The lores and ear-coverts have a blue-green gloss. It has black wings, with white tips on its inner secondaries, tertials, and greater wing-coverts. The white tips erode with age. The tail is black and has a shallow fork. The white-rumped swallow also has, as the name implies, a white rump. The rump is not totally white; it has some fine shaft streaks. The rest of the upperparts, in addition to the crown, nape, and forehead, are a glossy blue. These features, when this bird is not breeding, are more greenish-blue. The underparts and underwing-coverts are white. The bill, legs, and feet are black, and the irides are brown. The sexes are alike, and the juvenile can be distinguished by its dusky breast and the fact that it is duller and more brownish.<p>This swallow is similar to the Chilean swallow but can be differentiated by the Chilean swallow's lack of a supraloral white streak. The Chilean swallow also seems to keep its glossy blue upperparts when not breeding. The white-rumped swallow is, in addition, larger than the Chilean swallow.<p>The song of the white-rumped swallow is often described as a soft gurgling or a broken warble. It usually sings while flying at dawn. The call is described as a quick and toneless zzt. The alarm note it uses is short and harsh.

Taxonomía

The white-rumped swallow was first formally described as Hirundo leucorrhoa by French ornithologist Louis Pierre Vieillot in 1817 in his Nouveau Dictionnaire d'Histoire Naturelle. Subsequently, it was moved to its current genus, Tachycineta, which was created in 1850 by Jean Cabanis. The binomial name is derived from Ancient Greek. Tachycineta is from takhukinetos, "moving quickly", and the specific leucorrhoa is from leukos, "white", and orrhos, "rump".<p>The species was formerly considered a subspecies of the Chilean swallow, most likely due to the similarity in morphology and calls. It is occasionally placed in the genus Iridoprocne with the tree swallow, mangrove swallow, white-winged swallow, and Chilean swallow. A study of the mitochondrial DNA of Tachycineta supports the split, although studies do show that the white-rumped swallow forms a superspecies, leucorrhoa, with the Chilean swallow. This species is monotypic, with no known subspecies.<p>This swallow is named for its white rump but it is also sometimes called the white-browed swallow, due to its white supraloral streak.

Nombre científico

Tachycineta leucorrhoa

Autoridad

(Vieillot, 1817)

Orden

Passeriformes

Familia

Hirundínidos

Género

Tachycineta

Distribución y hábitat

This swallow is native to Argentina, Bolivia, Brazil, Paraguay, Peru, and Uruguay. It inhabits open and semi-open country near water, the edge of woodland, and human settlements. It also occurs in dry savannas, degraded former forest, and both subtropical and tropical seasonally flooded grassland. It is additionally known to occur in the pampas of Argentina and Uruguay. During the austral winter, the birds in the southern population usually move to the northern parts of its range. This bird can be found at altitudes ranging from sea level to 1,100 metres (3,600 ft).

Migración

Migrantes completos

Comportamiento

Patrón migratorio: Migrantes completos.

Conservación

Tendencia poblacional: en aumento.

Tendencia poblacional

en aumento